Powertrain, generic (extended)

P26E9 Actuator Supply Voltage D Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

The high fault of rail D is about voltage where none should be: the controller has turned supply D off, yet the line stays live. Either the high-side switch inside the module no longer opens or an outside wire touches battery positive. GM's 2023 and 2024 TCM tables check this for output 8 during shutdown; if the line holds more than 70 % of battery voltage with the output disabled, a shorted switch is noted in permanent memory and reported once the module wakes up again. Battery voltage must stay between 8.75 and 18 V and change by less than 1.5 V during the test, and GM rates the code Type B, so two failing trips light the lamp. Ford's 2024 summary names P26E9 as the shorted-switch fault of driver 8 in the TR9070. Because the loads can no longer be cut as a group, the module will normally fall back to a safe mode.

Likely causes

High-side switch in the control module stuck closed
Supply D wire chafed against a battery or ignition feed
Water or corrosion in the module connector creating a leakage path

Symptoms

  • Warning light on after two drive cycles
  • Transmission in limp mode or with restricted gears
  • Code appears after restarting rather than while driving

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,800
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

actuator supply dcontrol modulewiring harness

Related codes

P26E7P26E8P2686P2671P0659

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com.